Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Impaired remyelination and axonal degeneration may account for progressive disability in MS patients. As ciliary neurotrophic factor (CNTF) takes part in myelogenesis, we examined the frequency of a CNTF-null mutation in 349 MS patients with respect to their clinical presentation and in comparison with 434 healthy controls. Similar genotype frequencies for the CNTF mutation were obtained in MS patients (genotype 0101=74.8%, 0102=22.3%, 0202=2.9%) and controls (genotype 0101=71.7%, 0102=26.5%, 0202=1.8%) even after stratification for the HLA-DRB1*15 allele. In addition, there was no significant correlation of CNTF genotypes to age at onset, course or severity of the disease. We therefore conclude, that the requirement for CNTF in myelogenesis or cell survival may be bypassed by a second ligand or redundancy of functional activity of other neurotrophic factors.